Certain known belt conveyors of a modular type are formed by a succession of modules aligned with respect to one another along the ropes and stably connected together via the ropes themselves.
Each module comprises a rigid supporting frame of its own, which in turn comprises, for each top load-bearing rope, a row of top jaws for attachment to the top load-bearing rope itself and, for each of the bottom load-bearing ropes, a row of bottom jaws for attachment to the bottom load-bearing rope itself.
The frame supports a plurality of top idle rotating rollers configured to rest and guide, a concave forward or loading branch of a motor-driven conveyor belt, and a plurality of bottom rollers configured to support and guide a return branch of the conveyor belt itself.
The belt conveyor is progressively formed by installing in succession the various modules between the load-bearing ropes. In order to install the modules, an installation vehicle is provided, which comprises a carriage that is motor-driven or pulled by service ropes and is coupled to the top load-bearing ropes in order to displace in opposite directions along the load-bearing ropes themselves.
The carriage carries suspended therefrom a pair of supporting platforms for the staff responsible for installing, which are set on opposite lateral sides of the module that is being installed and of the load-bearing ropes and is provided with a device for attachment of the module during connection to the load-bearing ropes.
Even though known installation vehicles of the type described above are used, they render the operations of clinching of the jaws to the load-bearing ropes frequently problematical. Specifically, during lifting and positioning of each module, the top load-bearing ropes inevitably yield increasing their deflection and thus approaching the bottom load-bearing ropes Consequently, the effective distance between each top load-bearing rope and the corresponding underlying bottom load-bearing rope is instantaneously different from the distance according to the configuration and, in particular, different from the distance between the corresponding rows of top and bottom jaws. Following upon deflection, coupling of the jaws to the respective load-bearing ropes is possible only by moving the bottom load-bearing ropes away from the top ones, and this requires, in addition to a considerable physical effort, dedicated installation equipment, use of which is rendered relatively difficult by the relatively small extension of the supporting platforms.
The foregoing determines relatively long times and relatively high costs for assemblage of the modules.